Capacity Control Valve Structure for Pressure-Balanced Valve Body Control
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Solution Overview
Problem
The existing capacity control valves for variable displacement compressors suffer from reduced accuracy in controlling the valve body due to pressure differences between suction and control pressures, affecting the responsiveness and efficiency of the compressor.
Innovation Solution
A capacity control valve design where suction pressures are applied from both the pressure sensitive chamber and the accommodation chamber, with a communication hole for equalization and a groove to prevent control fluid leakage, allowing precise control of the valve body by balancing biasing forces with the solenoid's driving force.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If control pressure Pc is introduced to the accommodation space through a gap between the coupling bar and shaft hole, then the valve body can be actuated, but the accuracy of control is deteriorated due to pressure differences between suction and control pressures
Solution Approach 1:
The harmful control pressure Pc is extracted from the accommodation space by providing a communication hole that allows suction pressure Ps to be introduced, thereby removing the adverse pressure difference effect while maintaining valve actuation capability
Solution Approach 2:
Suction pressure Ps acts as an intermediary pressure that balances the pressure acting on the valve body from both the main valve chamber and accommodation space, eliminating the net pressure difference that degrades control accuracy
2Speed
If the communication hole is made large to improve pressure equalization, then the responsiveness improves, but the structural strength may be compromised
Solution Approach 1:
The communication hole is strategically positioned and sized to provide sufficient pressure equalization while maintaining structural integrity in critical areas of the valve housing, achieving local optimization of both fluid flow and structural properties
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This design enhances the precision and responsiveness of the valve body control, maintaining structural strength and reducing the influence of control pressures, thereby improving the operational efficiency of the compressor.
Implementation Method 1
a valve body that is opened and closed by electromagnetic force generated in a solenoid (80)
Implementation Method 2
a bellows (62) that is provided in a pressure sensitive chamber (60), in which the Ps port is formed, to apply biasing force to the valve body according to a surrounding pressure
Data Source
Figure 1
Figure 2
Figure 3
AI summary
There is provided a capacity control valve capable of precisely controlling a valve body. A capacity control valve V includes a valve housing 10 provided with a Ps port 13 through which a suction fluid at a suction pressure passes and a Pc port 12 through which a control fluid at a control pressure passes; a valve body 51 that forms a main valve 50 in cooperation with a valve seat 10a, the valve body coming into contact with and separating from the valve seat 10a, to close and open a communication between the Pc port 12 and the Ps port 13 by a driving force of a solenoid 80; and a pressure sensitive body 61 that applies a biasing force to the valve body 51 according to a surrounding fluid pressure. The suction fluid is supplied from the Ps port 13 to a pressure sensitive chamber 60 in which the pressure sensitive body 61 is disposed. An accommodation chamber 30 in which a rear side portion of the valve body 51 is accommodated is provided with a supply passage 14 to which the suction fluid is supplied.